They're all just revised versions of each other. They all have the same power potential, they just kept making the wastegate a bit better for each revision. I would go with the 43 or 48 though, because they seem to have fixed the wastegate cracking problem the 39 is known to have, even though it doesn't affect performance.

They're all just revised versions of each other. They all have the same power potential, they just kept making the wastegate a bit better for each revision. I would go with the 43 or 48 though, because they seem to have fixed the wastegate cracking problem the 39 is known to have, even though it doesn't affect performance.

so will they all bolt directly on w/o any modifications? and do i have to have the sti top mount for it to work?

Skip the VF series nonsense. They're not very efficient turbos and not rebuildable. They're also somewhat overpriced. They're popular because you can find used ones off of STi's, not because they're good. Look at a TD05 based mitsu turbo like a 16G or 18G.

For any turbo upgrade on your car, you will need:
-fuel pump
-injectors
-intercooler (top mounted is fine for a medium sized turbo)
-downpipe
-cat back
-decent tune

and people will recommend:
-3 port BCS
-intake
-budget for a transmission replacement

Skip the VF series nonsense. They're not very efficient turbos and not rebuildable. They're also somewhat overpriced. They're popular because you can find used ones off of STi's, not because they're good. Look at a TD05 based mitsu turbo like a 16G or 18G.

im not looking to make huge power i just want a reliable daily driver that makes about 260-280 whp...just something i can have fun with on the weekends.

A VF series will definatly get you to that number pretty easily for cheap then. If thats all you looking for. Go with a VF48 over the VF43 and VF39. I've seen a couple VF48'd 06-07 wrxs at my tuner and they make some damn good numbers for being a VF series turbo. Better than my VF39 did before my turbo swap. (OT, but one of the wrxs was my old 06 TR that the guy did the swap on and he ended up beating on the thing breaking the transmission a few weeks later. The guy did a lot more just swap turbos though.)

Yeah, if he's not looking to push the crap out of the VF turbo. Then the STI TMIC won't really hold it back that much if he's not looking to max out the turbo. If he was looking to max it out...then go aftermarket TMIC.